Biochar is widely applied in soil for agricultural and environmental purposes. Soluble fraction of biochar may be released from bulk biochar as dissolved biochar (DBC) after irrigation or rainfall. DBC had been reported to possess high chemical activity in aqueous system, while less attention was paid to the impact of DBC on the soil environmental processes. In this work, the impact of DBC on ferric (hydro) oxides was systematically examined. Our study showed that DBC prepared from rice straw could significantly promote the dissolution of ferric oxides with unstable and metastable crystalline structures, e.g., ferrihydrite under relatively acidic condition. Organic ligand-promoted dissolution was the main mechanism for iron release from ferrihydrite, and the low-molecular-weight DBC component (less than 1000 Da) was the major contributor for this process. Furthermore, the organic carbon content normalized ligand-promoted dissolution capacity for DBC was much higher than common dissolved organic matters. More importantly, DBC could promote the release of Cr from dichromate-adsorbed ferric mineral. Our results suggest that in soils with relatively low pH and high contents of ferric hydroxides, e.g., red soil in southern China, DBC derived from applied biochar could enhance the mobility and bioavailability of iron and other heavy metals. The dissolved metals would play active roles in soil redox cycle and biotic processes. Therefore, it's necessary to evaluate the long-term impact of biochar application on acidic field soils with high iron content.Understanding the processes of pollutants removal in soil remediation practices is crucial to apply the appropriate treatment method. Although widely employed in soil contamination events, the mechanisms of the Fenton reaction are still debatable. To investigate the catalytic performance of soils towards the degradation of p-xylene in Fenton reactions, we performed a series of experiments employing two soil samples with different physical-chemical properties, Oxisol and Alfisol. These soils were subjected to extraction procedures that separated the different types of pedogenic iron oxides (amorphous and crystalline) and produced soil fractions with different organic matter contents. We observed that Oxisol, which contains high amounts of amorphous pedogenic iron oxides, performed better in hydrogen peroxide decomposition and radical generation but worse in p-xylene degradation. These results originated from the presence of hematite in Oxisol, which has a lower catalytic activity than goethite, the pedogenic oxide present in Alfisol. Samples containing high concentrations of organic matter performed better in decomposing hydrogen peroxide but worse in degrading p-xylene due to the scavenging of active species by labile organic matter compounds.Boundary layer height (BLH) plays an important role in regulating global weather/climate, as well as the dispersion and transportation of pollutants. https://www.selleckchem.com/products/ml385.html Until now, however, the attribution and contributions of different controlling factors to BLH long-term variability and trends have not been quantified on a global scale. The long-term radiosonde dataset was used in this study to retrieve global BLH climatology; seasonal, diurnal, long-term variation and trends were analyzed over a 39-year period (1980-2018). Statistical results show that the global distribution of the BLH and its trend have apparent day-night differences. BLH during daytime is deeper during clear-sky conditions compared to cloudy sky conditions, indicating a significant effect of clouds; BLH during nighttime is deeper under cloudy conditions. BLH was also found to vary over different land types; dry and hot soil exhibits a deeper BLH than those of wet and cool soil. The long-term variation and trend of BLH are highly influenced by near-surface meteorological parameters. In particular, based on multiple linear stepwise regression models and the contribution calculation method, this investigation initiatively quantifies the influences of meteorological parameters on global BLH long-term variation and trend. Our results emphasized that a 10 m wind speed (WS) and low tropospheric stability (LTS) have significant contributions to long-term BLH variation; WS and LTS anomalies alternately dominated the contribution of the diurnal cycle of the BLH anomaly. Annual BLH recorded an average increasing trend (38.9-42.1 m/decade), and LTS is more dominant than WS from a contribution perspective, especially for increased BLH anomaly. Contributions from near-surface temperature (T) and relative humidity (RH) also play important roles. However, a decreasing WS trend dominated the decreased trends of BLH anomaly, accounting for nearly 40% of the total contribution.In this study, multi-walled carbon nanotubes modified by magnesium (Mg@CNT) was prepared as a novel adsorbent to recover phosphate from wastewater. Mg@CNT with the mass ratio of 0.48 (Mg versus MWCNTs) was the most efficient for phosphate adsorption and the maximum experimental adsorption capacity was up to 198 mg P/g. The Mg@CNT characterization was done by Field emission scanning electron microscope coupled with energy-dispersive spectroscopy detector (FESEM-EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), surface area analyzer (BET), Transmission electron microscope coupled with energy-dispersive spectroscopy detector (TEM-EDS). The MgO nanoflakes spread on the surface of multi-walled carbon nanotubes and reacted with phosphate to generate Mg3(PO4)2?10H2O as the end product. Phosphate adsorption on Mg@CNT was chemisorption onto heterogeneous surface according to the kinetic model and isotherm model fitting results. Several common co-existing ions, e.g., Cl-, NO3- and humic acid, had no obvious negative impact on the phosphate adsorption capacity; while SO42- and CO32- expressed stronger negative impacts and led to 13.2% and 39.5% decrease in phosphate adsorption capacity, respectively. After five adsorption-desorption cycles, Mg@CNT still maintained more than 80% adsorption capacity of the initial and high phosphate desorbability. These results implied that Mg@CNT possessed great application potential in phosphate recovery.